Linux Introduction

What is Linux?

Linux is an open-source Unix-like operating system kernel, first released in 1991 by Finnish programmer Linus Torvalds. Strictly speaking, "Linux" refers only to the operating system kernel, but in common usage, people use Linux to refer to the complete operating system based on the Linux kernel (also known as a Linux distribution).

History of Linux

Origins

• 1969: Unix operating system born at Bell Labs
• 1983: Richard Stallman launches the GNU project with the goal of creating a completely free operating system
• 1991: 21-year-old Linus Torvalds releases the first version of the Linux kernel (0.01)
• 1992: Linux adopts the GPL license and combines with the GNU project to form a complete operating system

Development History

1991 - Linux 0.01 released, supporting only Intel 386 processors
1994 - Linux 1.0 released, first stable version
1996 - Linux 2.0 released, supporting multiple processors
2003 - Linux 2.6 released, significant performance improvements
2011 - Linux 3.0 released
2015 - Linux 4.0 released
2019 - Linux 5.0 released
2022 - Linux 6.0 released

Why Choose Linux?

1. Open Source and Free

Linux is open-source software; anyone can use, modify, and distribute it for free. This means:

• No licensing fees
• Can view and modify source code
• Community-driven continuous improvement

2. Secure and Stable

• Strict permission management mechanism
• Fewer malware threats
• Servers can run for years without reboot

3. Highly Customizable

• From kernel to desktop environment, everything can be customized
• Rich selection of distributions
• Adaptable to various scenarios from embedded devices to supercomputers

4. Powerful Command Line

• Shell provides powerful automation capabilities
• Rich command-line tools
• Script programming capabilities

5. Wide Application Scenarios

• Server field: Over 90% of cloud servers run Linux
• Mobile devices: Android is based on the Linux kernel
• Embedded systems: Routers, smart TVs, IoT devices
• Supercomputers: 100% of the world's TOP500 supercomputers run Linux

Linux Distributions

A Linux distribution (referred to as Distro) is a complete operating system built on the Linux kernel, containing the kernel, system tools, applications, and a package manager.

Major Distribution Families

Debian Family

• Debian: Stable and reliable, suitable for servers
• Ubuntu: Most popular desktop distribution, beginner-friendly
• Linux Mint: Based on Ubuntu, offering a more traditional desktop experience

Red Hat Family

• Red Hat Enterprise Linux (RHEL): Enterprise-level commercial distribution
• CentOS / Rocky Linux / AlmaLinux: Free alternatives to RHEL
• Fedora: Cutting-edge technology, upstream of RHEL

Other Important Distributions

• Arch Linux: Rolling updates, highly customizable, suitable for advanced users
• openSUSE: Stable and feature-rich
• Gentoo: Source-code compilation, extreme optimization

How to Choose a Distribution?

User Type	Recommended Distribution	Reason
Beginners	Ubuntu / Linux Mint	Easy to install, rich documentation, active community
Developers	Fedora / Ubuntu	Recent software, comprehensive development tools
Server Administrators	Debian / Rocky Linux	Stable and reliable, long-term support
Advanced Users	Arch Linux	Complete control, rolling updates
Enterprise Users	RHEL / Ubuntu Server	Commercial support, certified training

Linux Compared to Other Operating Systems

Linux vs Windows

Feature	Linux	Windows
Cost	Free	Paid
Source Code	Open	Closed
Security	Higher	Average
Software Installation	Package manager	Download installer
Command Line	Powerful	Relatively weaker
Gaming Support	Limited (improving)	Rich
Hardware Compatibility	Good	Excellent

Linux vs macOS

Feature	Linux	macOS
Cost	Free	Requires Apple hardware purchase
Source Code	Open	Partially open
Customizability	Extremely high	Limited
Command Line	Bash/Zsh	Zsh (Unix-based)
Software Ecosystem	Rich	Excellent
Hardware Selection	Any	Apple only

Linux Application Fields

1. Servers and Cloud Computing

• Web servers (Apache, Nginx)
• Database servers (MySQL, PostgreSQL)
• Cloud platforms (AWS, Google Cloud, Azure extensively use Linux)

2. Development Environment

• Programming language support (Python, Java, C/C++, Go, etc.)
• Container technology (Docker, Kubernetes)
• Version control (Git)

3. Network Security

• Penetration testing (Kali Linux)
• Firewall and security tools
• Encryption and privacy protection

4. Scientific Computing

• High-performance computing
• Data analysis
• Machine learning

5. Embedded Systems

• Smart devices
• Industrial control
• Internet of Things

Tips for Learning Linux

1. Hands-On Practice

• Install a Linux distribution (you can use a virtual machine)
• Use Linux daily for your work
• Try to solve problems using the command line

2. Step-by-Step

• First master basic commands
• Understand the file system structure
• Learn Shell scripting
• Deepen your knowledge of system administration

3. Make Good Use of Resources

• Official documentation
• Online tutorials and videos
• Community forums (like Stack Overflow)
• man manual pages

4. Stay Curious

• The Linux world is vast with many areas worth exploring
• Continuously learn new tools and technologies
• Participate in the open-source community

Summary

Linux is a powerful, flexible, and open-source operating system, widely used in servers, development, embedded systems, and other fields. As a technical person, mastering Linux is an important fundamental skill.

In the following chapters, we will start with installing Linux and progressively learn about the file system, command-line operations, Shell scripting programming, and more, taking you through a comprehensive mastery of Linux usage skills.

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Next chapter: Installing Linux